Project Summary: The primary aims of this study are to: (1) Evaluate whether risk of perpetrating intimate partner aggression (IPA) when intoxicated is greater among young adults (aged 21 to 35 years) with attention-deficit hyperactivity disorder (ADHD) than young adults without ADHD, and (2) Investigate whether certain biological, neurological, and dispositional risk factors that may strengthen the risk of adults with ADHD perpetrating IPA when intoxicated. The long-term goal of this research is to evaluate whether alcohol consumption is a more potent risk factor for IPV in young adults with than without ADHD and, if so, to reduce their risk of IPA perpetration by including interventions to reduce their risk in existing treatments for ADHD. Young adults with ADHD are at-risk for IPV perpetration, and preliminary evidence indicates that problematic alcohol use is more likely to predict IPA among young adults with ADHD than those without ADHD. However, it remains unclear whether young adults with ADHD are more likely to perpetrate IPA when under the influence of alcohol and when provoked. Furthermore, investigations are needed to test whether specific biological (e.g., testosterone:cortisol ratio), neurological (e.g., behavioral inhibitory control), and dispositional risk factors (e.g., alcohol-aggression expectancies) identify adults with ADHD at increased risk of perpetrating IPA when intoxicated and provoked. To address these gaps in our knowledge, 66 heterosexual couples including young adults with ADHD and 34 heterosexual couples including young adults without ADHD will be recruited to participate in an alcohol administration study. Participants will be randomly assigned to either receive an alcoholic beverage or to receive a non-alcoholic beverage, and afterwards their level of partner-directed aggression in response to provocation will be unobtrusively measured via laboratory-based aggression task. We hypothesize that intoxicated adults with ADHD will perpetrate more severe IPA when provoked than sober adults with ADHD or adults without ADHD, regardless of being intoxicated or sober. Among adults with ADHD, we also hypothesize that individuals who are intoxicated and have specific biological, neurological, and/or dispositional traits will perpetrate more severe alcohol-facilitated IPA when provoked than intoxicated adults with ADHD but without the same traits, or adults with ADHD who are sober, regardless of their biological, neurological or dispositional traits. Finally, we hypothesize that adults with ADHD who have multiple risk factors will be at greatest risk of IPA perpetration when intoxicated.